SOURCE

const list  = []
for(let i = 0; i < 50000; i++) {
  list.push(i);
}
class App extends React.Component {
  constructor(props){
    super(props);
    this.state = {
      list
    } 
  }
  click(i) {
    return ()=>{
      list[i] = 'test'
      this.setState({
        list,
      })
    }
  }
  render() {
    return (
      <div>
        {this.state.list.map((v,k)=>{
          return(
            <h1 onClick={this.click(k)}>
              <span>
                <span>
                  <span>
                    <span>
                      Hello wolrd {k} {v}!
                    </span>
                  </span>
                </span>
              </span>
            </h1>
          )
        })}
      </div>
    )
  }
}

function render() {
  ReactDOM.render(
    <App />,
    document.getElementById('root')
  );
}

render();

<div id="root"></div>